Smoking-Cessation Drug Linked to Higher Cardiovascular Risks

​​By staff

Toronto—The risk of cardiovascular events increases when smokers use a commonly prescribed medication to kick the habit.

That’s according to a report in American Journal of Respiratory and Critical Care Medicine. Canadian researchers determined that users of varenicline, marketed as Chantix in the United States, were 34% more likely to have an emergency department visit or hospitalization for a cardiovascular event while on the medication. The increased incidence dropped to 12%, however, in patients who had not previously experienced a cardiovascular event.

The researchers conducted an observational, self-controlled trial to come to that conclusion. Among all patients, 3.95 adverse cardiovascular events per 1,000 varenicline users were documented that could be attributed to the drug, according to the authors, who write, “This is a figure that physicians can quote to their patients.”

In addition, a small increase in emergency department visits and hospitalizations for neuropsychiatric symptoms were noted but did not appear to be clinically meaningful, according to the researchers.

“Previous studies regarding the safety of varenicline have been conflicting and most examined people with relatively similar characteristics and backgrounds in highly controlled settings,” explained lead author Andrea S. Gershon, MD, an associate professor of medicine at the University of Toronto and a scientist at the Institute for Clinical Evaluative Sciences and Sunnybrook Health Sciences Centre in Ontario, Canada. “We wanted to study varenicline among all kinds of people in the real world.”

Medical records of 56,851 new users of varenicline between September 2011 and February 2015 living in Ontario were analyzed for the trial. From a year prior to the year following the date when varenicline was prescribed, 4,185 patients experienced cardiovascular events and 4,720 had neuropsychiatric events resulting in an emergency department visit or admission to a hospital.

Cardiovascular events including heart attack, stroke, arrhythmias, unstable angina, and peripheral vascular disease were among the cardiovascular events recorded with varenicline use, while depression, anxiety, psychosis, hallucinations, insomnia, and self-harm were among the neuropsychiatric events.

“Quitting smoking greatly reduces a person’s chances of developing heart disease and cancer and has many other health benefits,” Gershon pointed out. “Our findings should not be used to suggest people not take varenicline. The findings should be used to help people make an informed decision about whether they should take varenicline based on accurate information about its risks as well as its benefits.”